This invention relates generally to signal processing circuits, such as analog-to-digital converters and digital-to-analog converters.
Generally speaking, the resolving power of a digital signal converted from an analog signal is determined by the number of bits used in conversion, and its expressive power V is determined by: EQU V=1/2.sup.n
wherein the fullscale value is assumed to be 1.
Namely, the expressive power has no relation with the magnitude of the input analog signal, and therefore, a number of bits are necessary in order to convert an analog signal having a wide dynamic range. When it is intended to express an analog signal having a wide dynamic range by way of a small number of bits, the expressive power V has to be changed in accordance with the level of the input analog signal.